{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-107836 in the wild and no public exploit code.","fix":"No fix has been published for CVE-2026-107836 yet. Limit exposure of the affected software until one is available.","what":"CVE-2026-107836 is a high-severity vulnerability in RIOT-OS RIOT, published on 9 Oct 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link."},"fix_prompt":"Check this codebase for CVE-2026-107836 and fix it if it is affected.\n\nWhat it is: CVE-2026-107836 is a high-severity vulnerability in RIOT-OS RIOT, published on 9 Oct 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.\nExploitation: There is no known exploitation of CVE-2026-107836 in the wild and no public exploit code.\n\nAffected product: RIOT-OS RIOT. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-107836/ (Markdown: https://insights.sbomify.com/CVE-2026-107836/index.md)","id":"CVE-2026-107836","markdown":"https://insights.sbomify.com/CVE-2026-107836/index.md","name":"CVE-2026-107836","record":{"aliases":["GHSA-x924-p5fq-26pc"],"analysis":{"component_type":"operating_system","fix_type":"no_fix_stated","impacts":["denial_of_service","data_read"],"network_reachable":"yes","non_default_config":false,"product_category":"RIOT OS","requires_auth":"none","summary":"A malicious CoAP server can trigger an integer underflow in RIOT OS nanoCoAP client, causing a crash and potential memory disclosure.","user_interaction":"required","vuln_class":"integer_overflow"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[],"cvss":{"score":7.1,"severity":"high","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N","version":"4.0"},"cwes":[{"id":"CWE-191","name":"Integer Underflow (Wrap or Wraparound)"},{"id":"CWE-125","name":"Out-of-bounds Read"}],"description":"RIOT is an open-source microcontroller operating system designed for Internet of Things devices and other embedded systems. In 2026.07 and earlier, the nanoCoAP client function nanocoap_sock_get_slice() in sys/net/application_layer/nanocoap/sock.c accepts a Block2 response when _block_cb() sees the expected block number without also verifying that the server-controlled szx and derived offset match the requested block geometry. A malicious CoAP server can return the expected block number with a larger block size, causing the derived offset to exceed the client slice offset and making ctx-\u003eoffset - offset underflow in _2buf_slice(). The resulting buffer-relative calculation can read before the payload buffer and crash the client, causing denial of service and potentially exposing adjacent memory. No fixed release is available as of this review.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":false,"headline":"RIOT: nanoCoAP Block2 client slice handling underflows on inconsistent server-controlled block size","id":"CVE-2026-107836","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"integer_overflow","year":"2026"},"n_packages":0,"n_references":3,"next":{"headline":"RIOT: Out-of-Bounds Read in RIOT OS 6LoWPAN SFF Fragment Handling","id":"CVE-2026-107837"},"packages":[],"prev":{"headline":"OWASP Coraza WAF: Cookie Parser Confusion","id":"CVE-2026-107835"},"products":["RIOT"],"published":"2026-10-09","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-10-09","vendors":["RIOT-OS"]},"summary":"A malicious CoAP server can trigger an integer underflow in RIOT OS nanoCoAP client, causing a crash and potential memory disclosure.","url":"https://insights.sbomify.com/CVE-2026-107836/"}